The present invention can most advantageously be used in quadrature harmonic oscillators, synchronous detectors and devices for measuring the phase of an electrical signal against the background of noise.
A quadrature stepwave frequency converter is a device having two outputs and provided with one or two inputs for receiving the signals to be converted and with control inputs supplied with binary control signals so that the gain for the signal transmitted from the input of the device to its one output varies according to a predetermined periodic step function and the gain for the signal transmitted from the input of the device to its other output varies according to a periodic step function shifted in phase by 90.degree. in relation to the function characterizing variation of the gain for the signal transmitted from the input of the device to its first output.
Quadrature stepwave frequency converters must provide, on the one hand, a precise agreement between the law of variation of each of the gains and the corresponding step function waveform, and, on the other hand, a precise phase shift of 90.degree. between the curves characterizing variations of the gain.